import java.util.Scanner;
class  CC{
	public int C(int n,int m) {
                if(m>n) return -1;
                if(m ==n||m==0) return 1;
                else
                        return C(n-1,m-1)+C(n-1,m);
        }
}
public class test2{
	public static void main(String args[]) {
	       	System.out.print("n=：");
		Scanner reader = new Scanner(System.in);
		int n = reader.nextInt();
		System.out.print("\n");
		System.out.print("m=：");
                Scanner reader2 = new Scanner(System.in);
                int m = reader2.nextInt();
		System.out.print("\n");
		CC c = new CC();
		int sum = c.C(n,m);
		if(sum==-1) System.out.println("输入格式错误！");
		else
		System.out.printf("C(%d,%d)= %d\n",n,m,sum);
	}
}
